Tangrowth is a large Pokémon with a black body wrapped in a large mass of blue vines. The vines are used to entangle foes and prey. A pair of saucer-like eyes peeks out from beneath the tangled mess of vines. However, these eyes may be hidden in warm seasons due to how profusely the vines grow. Its stubby black feet are tipped with red. Tangrowth has a pair of blue boneless arms that have three fingers. The arms are made form bundles of vines. These fingers are completely red on a female Tangrowth, while they have red tips on a male.
Tangrowth is unfazed if one of its arms is broken off, as it will easily grow back. It will also rip apart vines off its body should they have grown too long. It hunts by disguising itself as a shrub, then grabbing prey with its vines. It can extend its arms as much as it wants. Predators like to eat Tangrowth's vines. When the climate is warm, its vine growth is accelerated. Tangrowth is very rare in the wild, though it can be found in temperate grasslands.
Tangrowth made its main series debut in Promoting Healthy Tangrowth!, where it was trying to save a dying tree that was a key part of the forest. With the help of Ash and his friends, it was able to save the tree.
Due to the mystery around Tangela's appearance under the vines, Tangrowth may be based on the swamp monster from the short story "It!" by Theodore Sturgeon, that is ultimately revealed to have formed around a human skeleton. It may also be based on a Green Man, a motif that is represented as a face surrounded by leaves and vines.
Its Pokédex entries state that its vines will bind and ensnare its surroundings. This may be a reference to thigmotropism, a biological reaction plants have towards contact that encourages them to coil around objects they touch as they grow, allowing stability in their stems and branches.
Tangrowth is a combination of tangle and growth.
Mojumbo is a combination of もじゃもじゃ mojamoja (shaggy or unkempt) and jumbo (referring to its size).